On Wed, Oct 25, 2006 at 02:34:28AM +0900, Atsushi Nemoto wrote: > Date: Wed, 25 Oct 2006 02:34:28 +0900 (JST) > To: ralf@xxxxxxxxxxxxxx > Cc: creideiki+linux-mips@xxxxxxxxxxxxx, linux-mips@xxxxxxxxxxxxxx > Subject: Re: Extreme system overhead on large IP27 > From: Atsushi Nemoto <anemo@xxxxxxxxxxxxx> > Content-Type: Text/Plain; charset=us-ascii > > On Tue, 24 Oct 2006 16:50:45 +0100, Ralf Baechle <ralf@xxxxxxxxxxxxxx> wrote: > > > 2. Timekeeping is broken. The clock in /proc/driver/rtc seems correct, but > > > the system clock advances at about 1/16 of real time. > > > > This one was caused by changeset ebca9aafa9bd5086d9f310205a8e30e225c5a5a6 > > which apparently wasn't quite ripe. You can work around it by > > revoking this changeset for now. The time damage affects other systems > > as well ... > > Now I'm looking my patch again but still can not find any problem... > > One question: > > > # zcat /proc/config.gz | grep HZ | grep -v ^# > > CONFIG_HZ_250=y > > CONFIG_SYS_SUPPORTS_ARBIT_HZ=y > > CONFIG_HZ=250 > > IP27 really supports HZ=250 ? Arbitrary frequency actually. The timer used is the HUB timer which is running at 800ns afair. It's like 53 bits or so. There is also a compare register so it's somewhat similar to the cop0 counter / compare timer. Ralf
